Abstract: The main control system is the core component of a large-scale wind turbine. This paper presents a main control system based on PLC, aiming to realize safe and stable operation for a 2 MW direct-driven permanent magnet wind turbine under unattended operation. The graded alarms based on the state code and the automatic start-up and shut-down system (APS) based on the state machine are introduced. An approach of event snapshot based on the ring buffer with sliding window scrolling update is designed to enhance the system analysis capabilities after incidents. A real-time simulation support platform is built on the basis of GH Bladed software to verify the torque–pitch joint control strategy. The software and hardware architectures are both expounded, and the overall development of the controller logic configuration was completed with Bachmann M-PLC software. The main control system has been successfully applied to a wind farm in Shandong Province, realizing unattended operation. The measured data of the wind turbine in a project site shows that the main control system is safe and stable and the control strategy is effective, providing a reference for the design and development of the main control system in similar wind turbines.